We can simplify BlobStorageData by reusing what we have in BlobData. Thus we do not need to define separate BlobStorageDataItem.
Created attachment 64737 [details] Proposed Patch
Created attachment 64738 [details] Proposed Patch Removed unwanted project.pbxproj change.
Comment on attachment 64738 [details] Proposed Patch R=me
Committed as http://trac.webkit.org/changeset/65622.